When it comes to men and their sexual peak, there's a widespread notion that men reach the pinnacle at 18 -- and remain there throughout their 20s. "Magic Mike" (the original film and the sequel) aside, is there any truth to the notion that a man in his 20s is at his sexual prime?
Studies show that the male sex hormone, testosterone, begins to peak as a man moves from his teens into his 20s. By age 18, male testicles are producing the most testosterone they ever have -- or will -- in a man's lifetime. This results in erections that are fast and firm, and a heightened degree of sexual desire. The story doesn't end there, though.
This increase in testosterone is more of a gentle ascent than blast-off; it begins to peak at age 18, continues throughout a man's 20s and then spikes around age 30. At least one poll illustrates this, with male respondents self-reporting they reached their sexual peak at an average age of 33 [source: Fetters].
The notion that a peak in testosterone is not a necessarily a sexual peak is one worth noting. A rise in testosterone doesn't translate to the penultimate sexual experience. Men can continue to experience a strong sex drive well into their golden years, decades after they were to have reached maximum testosterone levels.
Although physicians caution there will be some degree of decline in libido with age, a massive loss of sex drive is usually related to another issue, such as depression or stress, or an endocrine problem causing male sex hormones to plummet unnaturally. Occasionally, the side effects of prescription medication can diminish sex drive. Otherwise, most men remain sexually interested and active into their 70s, 80s and beyond [source: Nippoldt].
After testosterone peaks -- and remains strong -- during a man's 20s, his 30s usher in a drop in testosterone levels. This drop continues, at a rate of about 2 percent, for the rest of his life. A decrease in testosterone can affect the efficacy of erections, as well as libido. It affects other areas of life, too, by increasing moodiness and decreasing muscle tissue. In turn, this decreased muscle tissue makes it more difficult to burn calories, making it easier to gain weight -- a reality that could be avoided by an active sex life. After all, a make-out session will burn 238 calories in just 30 minutes [sources: Murphy, Jio].